Studies have shown that stem cells and their derivatives, including conditioned media (CM), have inhibitory effects on skin pigmentation. However, evidence supporting the skin brightening effect of exosomes derived from stem cells is lacking. We studied the antipigmentation effect in vitro and skin brightening efficacy in vivo of exosomes derived from human adipose tissue-derived mesenchymal stem/stromal cells (ASC-exosomes). Exosomes were isolated from the CM of ASCs using the tangential flow filtration method. ASC-exosomes reduced intracellular melanin levels in B16F10 melanoma cells regardless of the presence of the α-melanocyte-stimulating hormone (α-MSH). The skin brightening efficacy of a cosmetic formulation containing ASC-exosomes was assessed in human volunteers with hyperpigmentation in a prospective, split-face, double-blind, randomized placebo-controlled study. The ASC-exosome-containing formulation statistically decreased the melanin contents compared to the placebo control. However, the melanin-reduction activity was limited and diminished along with time. A further improvement in efficient transdermal delivery of ASC-exosomes will be helpful for more profound efficacy. In summary, these results suggest that ASC-exosomes can be used as a cosmeceutical for skin brightening.

The present study aimed to investigate the molecular mechanism of quercitrin, a major constituent of Hottuynia cordata extract, for its hair growth stimulating activities in cultured human dermal papilla cells (hDPCs). Quercitrin enhanced the cell viability and cellular energy metabolism in cultured hDPCs by stimulating the production of NAD(P)H and mitochondrial membrane potential (ΔΨ). The expression of Bcl2, an essential marker for anagen hair follicle and cell survival, was increased by quercitrin treatment. Quercitrin also increased the cell proliferation marker Ki67. The expression of growth factors—such as bFGF, KGF, PDGF-AA, and VEGF—were increased by quercitrin both in mRNA and protein levels. In addition, quercitrin was found to increase the phosphorylation of Akt, Erk, and CREB in cultured hDPCs, while inhibitors of MAPKs reversed the effects of quercitrin. Finally, quercitrin stimulated hair shaft growth in cultured human hair follicles. Our data obtained from present study are in line with those previously reported and demonstrate that quercitrin is (one of) the active compound(s) of Hottuynia cordata extract which showed hair growth promoting effects. It is strongly suggested that the hair growth stimulating activity of quercitrin was exerted by enhancing the cellular energy metabolism, increasing the production of growth factors via activation of MAPK/CREB signaling pathway.

Namkoong S, et al. Ann Dermatol. 2013 Feb;25(1):67-72. http://dx.doi.org/10.5021/ad.2013.25.1.67

Chung J, et al. Ann Dermatol. 2011 Dec;23(Suppl 3):S398-S401. http://dx.doi.org/10.5021/ad.2011.23.S3.S398